Field of the Invention
This invention relates to the fields of medical diagnostics, telemedicine, mobile health, wireless health, and any application of hyperspectral imaging based upon a mask of individual pixel filters.
Description of Related Art
Hyperspectral imaging is an imaging modality that gathers continuous information across a vast portion of the electromagnetic spectrum, as opposed to traditional imaging modalities (e.g., a conventional digital otoscope (such as the digital otoscope shown and described in U.S. 2008/0051637)), which generate three bands (red, green, blue (RGB)) per image. Accordingly, hyperspectral cameras and sensors and associated image processing systems have the ability to determine unique hyperspectral fingerprints, or “signatures”, known as “spectral signatures,” where each extra-visible wavelength is assigned, and may be displayed as a visible ‘false’ color. For example, in agricultural and geologic applications, these signatures may be specific to plant species or oil materials, respectively. For medical applications, the majority of hyperspectral imaging has been used to assess superficial skin perfusion via differentiation between oxyhemoglobin and deoxyhemoglobin. This application has been implemented in numerous clinical settings, such as tumor identification and wound healing processes.
While conventional hyperspectral imagers are expensive and bulky, recent developments are leading to smaller hyperspectral imaging systems, such as the system described in U.S. patent application Ser. No. 11/642,867. One example of an available hyperspectral camera is the “Spectral Camera HS”, manufactured by Spectral Imaging, Ltd in Oulu, Finland. This camera is configured to capture hyperspectral images in the 380-800 nm and 400-1000 nm spectral ranges. Based upon the availability of such miniaturized hyperspectral image sensors, they may be used in connection with devices or applications where conventionally monochrome or RGB image sensors are being used.
As is known, a hyperspectral cube (a “hyper-cube”) is a four-dimensional datacube (including free parameter and intensity), which illustrates or depicts the electromagnetic spectrum of a surface across a very broad visible and extra-visible spectral range. Such a hyper-cube is a three-dimensional hyperspectral image data set, which illustrates the electromagnetic spectral content of a two-dimensional image spectral range. The cube has axes of spatial dimension (X), spatial dimension (Y), and wavelength, and it represents a complete possible spectral reflectance analysis of a surface. The cube represents a stacked set of two-dimensional monochrome frames, scenes or images, with each frame, scene or image corresponding to the light intensity at a given spectral band. Since a hyperspectral image contains a full spectral profile of each pixel, the image may be used in determining or obtaining useful information and data.